Current Transformer (CT) analyzer UHV-105A

Potential/Voltage Transformer (PT)for electrical networksfor testing

The UHV-105A CT/PT Characteristic Tester is a portable instrument for on-site verification of protection-class current transformers (CTs) and voltage transformers (PTs). It integrates excitation characteristic (knee-point/saturation), ratio and polarity tests, load and insulation checks, onboard reporting and USB data export to streamline field verification workflows.

Key features

• Portable, field-ready enclosure with compact footprint and handling features for on-site use (lightweight design).
• Intuitive smart controller with integrated LCD for test control and result display.
• Built-in micro printer for immediate field reports and markings.
• Battery-backed non-volatile storage for up to 3,000 test sets.
• USB data export for report generation (Word) and laboratory post-processing.

Functions

• Current Transformer (CT)
• Magnetization / excitation characteristic measurement (knee-point and saturation determination).
• Transformation ratio (turns/ratio) test and accuracy verification.
• Polarity check.
• Derivation of 5% and 10% error curves.
• Current injection for ratio and accuracy testing, including FAST TEST mode.
• Withstand test of secondary winding with power-frequency alternating current.
• Automatic calculation of excitation knee-point value.
• Actual secondary load (burden) test and resistance measurement.
• Voltage Transformer (PT)
• Excitation characteristic test.
• Transformation ratio test.
• Polarity verification.
• Withstand (power-frequency) test of secondary winding.
• Resistance measurement and knee-point calculation.
• Actual secondary load test.

Technical specifications

• Operational power supply: AC 220 V ±20 V, 50–60 Hz.
• Equipment output waveform: sinusoidal.
• Single-machine output voltage (excitation characteristic): 0–1200 V.
• Excitation current set range: 0–20 A.
• Single-machine output current (transformation ratio test): 0–1000 A.
• CT ratio measurement range: 5–25000 A / 5 A (5000 A / 1 A).
• PT ratio measurement range: 1–500 kV.
• Load (burden) range: 5–500 VA.
• Resistance measurement range: 0.1–300 Ω.
• Accuracy (Error): ≤ 0.5% (0.3% × Reading + 0.2% × Range).
• Operating temperature: -10 ℃ to +40 ℃.
• Relative humidity: < 90% RH.
• Altitude: ≤ 1000 m.
• Overall dimensions (L × W × H): 450 × 350 × 350 mm.
• Weight: ≤ 28 kg.

Ensure the safety and stability of the power system

• Accident prevention: Transformers are key components of relay protection systems, and their performance directly affects the accuracy of fault diagnosis. The tester can detect potential hazards such as insulation aging and inter turn short circuits in transformers in advance, avoiding protection refusal or misoperation.
• Optimize operation: By detecting the load characteristics of the transformer (such as secondary circuit impedance), ensure that it operates within the rated load range, and prevent accuracy degradation or thermal damage caused by overload.
• Compatibility verification: Test the compatibility between transformers, energy meters, and protection devices to ensure the overall performance of the metering system or protection circuit.